Indiana has lost 95 percent of its wetlands since the 1800s, mostly to agricultural and housing developments. But salamanders can teach scientists a lot about wetland health. Indiana Public Broadcasting’s Nick Janzen brings us to a salamander research site in one the largest wetland restoration projects in the state.
Biology professor Mark Jordan and two of his students, Zach Jones and Shannon Calder, are searching for salamander larvae in Eagle Marsh, near Fort Wayne. Sitting on over 700 acres, it’s one of the largest wetland restoration projects in the state.
A healthy wetland is a really dynamic environment. Some parts of the year it’s underwater and sometimes it’s not, the ground freezes and thaws—and salamanders need that variability.
Standing in water-proof hip waders, Jordan explains how he and his students will catch the salamander larvae. “So we’re just gonna be using the dip nets trying to find salamander larvae,” he says. “We put the net down into the water until it hits the substrate, then we just bounce it on the bottom while we drag it back and see what we pull up.”
Salamanders play a role in wetland conservation. Scientists can evaluate the health of a wetland based on how many different salamander species live in it. There are over 20 types of salamander in Indiana. But today, Jordan and his students are searching for one particular kind: the unisexual ambystoma.
After searching for about 20 minutes, Calder finally catches a particularly active larva. “Looks like he’s either a smallmouth or unisexual, but I can’t see his chin.”
“That one’s probably a small-mouthed,” Jordan says. “It’s got lots of speckles on its chin.”
Jordan researches the unisexuals’ unusual reproductive system, but they’re are also useful because they interact with many different salamander species. Bruce Kingsbury, a biology professor at Indiana University-Purdue University Fort Wayne (IPFW), says the simple presence of these salamanders is a good indication of the wetland’s health.
“So where you have those species, that tells us that you have a healthier environment where they do have those shallow, usually temporary wetlands, that they need to be successful,” he says.
Kingsbury is also the director of the Environmental Resources Center at IPFW, a research and outreach organization. He says many people don’t appreciate the intrinsic value of each species, instead only seeing how they benefit people.
“Really my feeling is [an animal] doesn’t need to be good for us in an economic sense,” Kingsbury says. “And one analogy is that they’re works of art, and that we don’t like Mona Lisa just because you can sell it and make a bunch of money. People actually like to just look at it.”
Back at Eagle Marsh, Jordan and his students are finished collecting larvae. They’re standing in the parking lot using the trunk of Jordan’s car as a makeshift lab-bench, taking notes on the larvae they caught. The larvae are funny looking, about an inch long, sort of like a slimy lizard. When they’re in water, their external gills flair out, making them look like tiny dragons.
The scientists will take DNA samples and study the unisexuals’ genetic background, which can get really complicated. While some might have father salamanders, most of them are clones. All of the salamanders in this species are female. When they mate—with males from up to five different species—the males don’t impregnate the females, most of the time. Usually, mating triggers asexual reproduction.
“There’s a lot of interesting wildlife in Indiana,” Jordan says. “I came here, I had no idea that unisexual salamanders were here or even what they were, but it’s just one example of the diversity that we have around here that’s not widely recognized and people should take note of that and enjoy it as much as they can.”
